Infant cognition: going full factorial with pupil dilation

Abstract

The violation-of-expectation (VOE) paradigm and related methods are the main tools used to study high-level cognition in preverbal infants. Infants' differential looking to conceptually implausible/impossible events has been used as an index of early cognitive competence in many areas, including object knowledge, physics, language, and number. However, an event's plausibility is commonly confounded with its perceptual novelty or familiarity, leading to a variety of interpretations for looking time data (Bogartz, Shinskey & Speaker, 1997). This illustrative study demonstrates the value of factorial designs, in which perceptual (novelty-familiarity) and conceptual (possible-impossible) variables are independently and jointly explored. It also introduces pupil dilation as a viable and complementary dependent measure to study infant cognition. We show that pupil data can assist in the interpretation of otherwise equivocal looking time data. The discussion focuses on methodological considerations in infancy research.

Pupil diameter measurement errors as a function of gaze direction in corneal reflection eyetrackers

“…Missing values for pupil diameter (e.g., eye blinks) were recorded as −1 on Tobii systems and as 0 on the EyeLink eyetracker. Missing values were problematic and were interpolated before running the analyses, using a method described in Jackson and Sirois (2009). Pupil data from each eye were regressed on each other to fix missing samples when they applied to only one eye.…”

“…Therefore, it is an excellent methodological option for studying preverbal participants such as infants. It has been used to assess classical violations of expectation tasks (Jackson & Sirois, 2009;Sirois & Jackson, 2012), individual differences in face processing (Gredebäck, Eriksson, Schmitow, Laeng, & Sternberg, 2012), and perception of irrational events by infants (Gredebäck & Melinder, 2010. Task-elicited changes in pupil diameter have also been studied in adults (see Beatty, 1982, for a review) with, for example, eye saccade tasks (Evens & Ludwig, 2010), Stroop tasks (Brown et al, 1999;Laeng, Orbo, Holmlund, & Miozzo, 2011;Siegle, Steinhauer, & Thase, 2004), and dual tasks (Karatekin, 2004;Karatekin, Couperus, & Marcus, 2004).…”

The developing cognitive substrate of sequential action control in 9- to 12-month-olds: Evidence for concurrent activation models

“…The paradigm uses eye movements as actions, which is appropriate since infants can accurately control their eye movements from at least 4 months of age (Scerif et al, 2005) and these can be considered voluntary goal-directed actions (Gredebäck & Melinder, 2010;Falck-Ytter, Gredebäck, & von Hofsten, 2006;Perra & Gattis, 2010;Senju & Csibra, 2008;). An additional advantage of our paradigm is the concurrent recording of Task-Evoked Pupillary Responses (TEPRs) which is relatively new in developmental research (Falck-Ytter, 2008;Jackson & Sirois, 2009;Laeng, Sirois & Gredebäck, 2012;Verschoor et al, in press). …”

Steganography on RGB Images Based on a “Matrix Pattern” using Random Blocks

“…To reach the brightness of any image, first of all green, red and blue layers of image are separated. Secondly, using (3), the brightness is calculated [25,26] on image brightness than other layers. Thus, to increase the transparency of the stego-image, the blue layer is used in this paper.…”